Recently, with the widespread use of the Internet as a background, user demands for browsing contents described by a markup language such as an HTML (hypertext markup language) on a portable device such as a mobile phone and a PDA (personal digital assistant) are now increasing.
Typically, the contents on the Internet are targeted for a personal computer having a relatively large screen which is larger than a screen size of the portable device. That is, the contents targeted for the personal computer include images and tables whose sizes are larger than the screen size of the portable device. For this reason, in many cases, the portable device having a relatively small screen can not suitably display the contents of the Internet on the screen thereof.
The table, which is defined in the contents by a tag <table>, is used to lay out cells of the table in a form of a two-dimensional array on a device. In addition, by utilizing the table, a relatively large image can be displayed on the screen of a device as a combinational image consisting of a plurality of cells of partial images.
A method of browsing contents targeted for the personal computer using the portable device having relatively small screen has been proposed. This method includes aligning cells, which are aligned horizontally (i.e., in a direction of a row) in a table of the contents, vertically on the screen of the portable device. By adopting the method, the browser running on the portable device enables a user to browse the cells on the relatively small screen of the portable device by scrolling vertically the cells by operating, for example, an up-and-down key.
However, if the cells, which are aligned horizontally in original contents, are aligned on the screen of the portable device vertically, the significance of alignment of the cells which are aligned in the original contents in a form of a two-dimensional array may be lost.
Japanese Patent Provisional Publications No. HEI 9-9160 (document 1) and No. 2001-243151 (document 2) disclose a technique to scale down an image in original contents in accordance with the screen size of the portable device. By adopting the technique disclosed in the documents 1 and 2, the browser running on the portable device can display the image of the original contents within the screen of the portable device. However, in the documents 1 and 2, no explanation is made on how to display a table on the relatively small screen of the portable device without losing the significance that the two-dimensional array of the table has.
Another factor that inhibits comfortable browsing of the contents targeted for the personal computer on the portable device is a “frameset” which is defined in the contents by a set of tags <frameset> and </frameset>. The tag <frameset> is a declaration statement used to divide the screen into a plurality of frames to display different contents on the respective frames. In the frameset, contents having a URL (uniform resource locator) designated by a tag <frame src=“ . . . ”> are displayed in one frame.
Similarly to the table defined by the tag <table>, by using the frameset, contents can be displayed on a screen of a device in a form of a two-dimensional array. However, in a case where the contents including the frameset are displayed by the browser on the relatively small screen of the portable device, one of URL contents designated by the tag <frame src=“ . . . ”> is displayed in a small section (i.e., one frame) of the relatively small screen of the portable device. In this case, the URL content may be difficult to be read. That is because the browser running on the portable device simply divides the screen into a plurality of frames and arranges the frames in a form of a two-dimensional array in accordance with tags <frame cols=“,”> and <frame rows=“,”> described in the frameset.
That is, a screen size per a frame becomes very small when the frameset is displayed by the browser on the relatively small screen of the portable device.
Japanese Patent Provisional Publication No. 2000-298543 (document 3) discloses a method to indicate an active frame of a plurality of frames by a heavy line, and to use a frame switching key to switch between the frames when the frameset is displayed by a browser on a computer.
By adopting the technique disclosed in the document 3, the browser enables the user to recognize the active frame visually and to switch to a desired frame relatively easily by using the frame switching key. However, in the document 3, no explanation is made on how to display the frameset on the relatively small screen of the portable device without losing the significance that the two-dimensional array of the frames of the frameset has.